start implementing messages to background APIs (text file download)

manifest.json

@@ -37,7 +37,8 @@
 		"<all_urls>",
 		"storage",
 		"menus",
-		"tabs"
+		"tabs",
+		"downloads"
 	],
 	"version": "0.0",
 	"manifest_version": 2,

src/kiss_web_pad/Background_.kiss

@@ -1,3 +1,6 @@
+(import js.html.File)
+(import js.html.URL)
+
 (defMacroVar mainKissFile kissFile)
 (loadFrom "kiss-firefox" "src/kiss_firefox/Util.kiss")
 (loadFrom "kiss-firefox" "src/kiss_firefox/BackgroundUtil.kiss")
@@ -10,4 +13,12 @@
 (onMessage "savePad" [pad]
 	(WebPad.save ~pad))
 
+(onMessage "downloadTxtFile" [filename contents]
+	(let [file (new File [contents] filename)
+			url (URL.createObjectURL file)]
+		(awaitLet [txtDownloadId (API.browser.downloads.download (objectWith url filename))]
+			(catch [e] (sendResponse e))
+			(API.browser.downloads.show txtDownloadId)
+			(sendResponse "done"))))
+
 // TODO accept and respond to messages from other extensions requesting the content of the current page's pad

src/kiss_web_pad/Main_.kiss

@@ -43,6 +43,7 @@
 				->e (let [interp (new KissWebPadInterp)]
 						(dictSet interp.globals "document" document)
 						(dictSet interp.globals "window" window)
+						(dictSet interp.globals "sendMessage" sendMessage)
 						(interp.evalCC (editor.getValue) ->:Void v (print v))))))
 	(if showing
 			(document.body.removeChild div)